Disc inverting mechanism and disc automatic changer with the mechanism

ABSTRACT

A rotating frame  22  is supported by a stationary frame  21  rotatably by 180 degrees, and in both side plates  22   c  of the rotating frame  22,  there are formed four pairs of guide grooves  25-28  for guiding pallets  9  and slots  32   a   -32   d  for moving claw members  30, 31,  said slots corresponding to said guide grooves  25-28.  On an inner wall of a rear plate  22   b  of the rotating frame  22,  there is provided an up and down movable member  47  which moves downward together with the claw members  30, 31  when the rotating frame  22  is rotated by 180 degrees. Into the first and third guide grooves  25  and  27,  there have been previously inserted empty pallets  9  with such a posture that their front surfaces  11  face downward. By moving the claw members  30, 31  along the slots  32   b,    32   d,  the pallets  9  having discs D placed thereon are drawn into the second and fourth guide grooves  26  and  28  such that these pallets  9  are opposed to the upper empty pallets  9.  In this condition, when the rotating frame  22  is rotated by 180 degrees, the discs D are turned-over and are placed on the lower empty pallets  9.

TECHNICAL FIELD

The present invention relates to a disc turn-over mechanism forturning-over discs such as CD and DVD, and an automatic disc exchangeapparatus comprising said mechanism for use in a storing device of acomputer and others and a recording and reproducing device of AVequipments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a first embodiment;

FIG. 2 is a perspective view illustrating a turn-over and hand-overmechanism together with a pair of pallets;

FIG. 3 is a partially enlarged plan view of the turn-over and hand-overmechanism;

FIG. 4 is a perspective view showing the turn-over and hand-overmechanism in a condition in which a rotating frame is rotated by 90degrees;

FIG. 5 is a side view representing the rotating frame;

FIG. 6 is a partially enlarged perspective view of the rotating framecorresponding to FIG. 4;

FIG. 7 is a view explaining the operation;

FIG. 8 is a view explaining the operation;

FIG. 9 is a view explaining the operation;

FIG. 10 is a view explaining the operation;

FIG. 11 is a view explaining the operation;

FIG. 12 is a perspective view of a second embodiment; and

FIG. 13 is a perspective view of a turn-over mechanism.

TECHNICAL BACKGROUND

Heretofore, discs such as FD and MO are installed within cases toconstitute cartridges, and in an automatic disc exchange apparatus, theexchange of discs is performed by exchanging cases between a storingmeans and a recording and reproducing apparatus. Therefore, when bothfront and rear surfaces of a disc are used as the recording surface, inthe automatic disc exchange apparatus, the disc turn-over can be carriedout by turning-over a case upside down.

Recently there have been developed discs such as CD and DVD which arenot installed within cases. In the automatic disc exchange apparatus,such a disc is placed on a tray-like pallet and the pallet istransported between the disc storing means and the recording andreproducing apparatus. Therefore, when both front and rear surfaces ofsuch a disc are usable, it is necessary to turn-over the disc placed onthe pallet in the automatic disc exchange apparatus. However, if thepallet having a disc placed thereon is turned-over, the disc is droppedoff the pallet.

It is an object of the present invention to provide a disc turn-overmechanism, which overcomes the above mentioned problem and can turn-overa disc whose front and rear surfaces are usable as the recordingsurface.

It is another object of the invention to provide an automatic discexchange apparatus, in which a disc can be turned-over during atransportation between a disc storing means and a recording andreproducing apparatus.

DISCLOSURE OF THE INVENTION

According to the invention, a disc turn-over mechanism comprises atleast one pair of first and second pallets, and a turning-over means forturning-over said first and second pallets, wherein said first pallet onwhich a disc is placed and said second pallet on which no disc is placedare stacked one on the other, and the turned-over disc is transferredonto the second pallet by turning-over the first and second pallets bysaid turning-over means.

According to the invention, an automatic disc exchange apparatuscomprises a storing means for storing discs, a recording and reproducingapparatus for recording and reproducing information on and from saiddiscs, a transporting means for transporting said discs between saidstoring means and said recording and reproducing apparatus, and aturn-over mechanism for turning-over the discs, wherein said turn-overmechanism includes at least one pair of first and second pallets and aturning-over means for turning-over said first and second pallets, saidfirst pallet on which a disc is placed and said second pallet on whichno disc is placed are stacked one on the other, and said disc isturned-over and the turned-over disc is transferred onto the secondpallet by turning-over the first and second pallets by said turning-overmeans.

BEST MODE OF PRACTICING THE INVENTION

Now the present invention will be explained in detail with reference tothe accompanying drawings.

FIG. 1 is a perspective view showing a first embodiment, in which a partof a housing 1 is denoted by an imaginary line. On a base platform 1 aprovided at a bottom of the housing 1, there are arranged, on a samecircle, storing boxes 2 in each of which a number of information recordmedium, i.e. discs such as CD and DVD installed within thin flatplate-like pallets are stored, and a recording and reproducing drive 3for recording and reproducing information on and from the discs. Withina space surrounded by these storing boxes 2 and recording andreproducing drive 3, there is arranged a transporting mechanism 4 fortransporting pallets having discs placed thereon between the storingboxes 2 and the recording and reproducing drive 3. In the presentembodiment, three sets of arrays of the storing box 2 are arranged onthe same circle and one set of array of the recording and reproducingdrives 3 is arranged on the same circle.

The transporting mechanism 4 includes upper and lower discs 5 and 6which are arranged rotatably about a center line A of the circle alongwhich the storing boxes 2 and recording and reproducing driver portion 3are arranged. To these discs 5, 6 is secured a post 7 at an eccentricposition, and a turn-over and hand-over mechanism 8 for handing-over apallet having a disc placed thereon between the storing boxes 2 and therecording and reproducing drives 3 and for turning-over a received disctogether with the pallet is supported by the post 7. The turn-over andhand-over mechanism 8 is movable up and down along the post 7 and isrotatable about a center line A together with the post 7. There areprovided driving mechanisms for rotating the discs 5, 6 and moving theturn-over and hand-over mechanism 8 up and down such that the turn-overand hand-over mechanism can be indexed at a desired storing box 2 aswell as a desired recording and reproducing drive 3, but these mechanismare not shown in the drawing.

FIG. 2 is a perspective view showing the turn-over and hand-overmechanism 8 together with a set of pallets 9. The present turn-over andhand-over mechanism 8 can contain two sets of pallets 9. That is to say,two empty pallets 9 which do not contain a disc D are installed withinthe turn-over and hand-over mechanism 8 with interposing a spacingtherebetween, and further two pallets 9 each containing a disc D may beinserted into spaces formed underneath the previously installed pallets9.

These four pallets 9 may be retained within the turn-over and hand-overmechanism 8 or may be discharged from the turn-over and hand-overmechanism 8 by means of two pairs of claw members which will beexplained later. Within the turn-over and hand-over mechanism 8,adjacent pallets 9 are stacked to be opposed to each other, and thestacked pallets 9 are turned-over by 180 degrees, while the disc D isprevented from dropping off the pallets.

Now it is assumed that a direction in which the pallets 9 are insertedinto the turn-over and hand-over mechanism 8 is denoted as a forwarddirection. Then, the pallet 9 is formed symmetrical in the forward andbackward directions as well as in the right and left directions. Thepallet 9 comprises a front surface 11 on which a disc D is placed, arear surface 12 opposite to the front surface, and a pair of projections13 which are gripped by claw members as will be explained later.

In the front surface 11 of the pallet 9 there is formed a circulardepressed portion 14 for containing the disc D, and the circulardepressed portion 14 has a circular window 15 whose diameter is smallerthan that of the disc D. At a corner of the circular depressed portion14 there is formed a step not shown, and the circular depressed portion14 has a diameter which is sufficient for containing the disc D thereinand a diameter of the step is such that the record surface of the disc Dis not brought into contact with the pallet even if the disc deviateswithin the circular depressed portion 14.

Therefore, the two pallets 9 which have been previously installed in theturn-over and hand-over mechanism 8 have the rear surfaces facingdownward, and the pallets 9 containing the disc D are installed belowthe previously installed pallets 9 such that their front surfaces 11 areopposed to each other.

The turn-over and hand-over mechanism 8 comprises a stationary frame 21provided on the post 7 in such a manner that the stationary frame 21 ismovable up and down, and within the stationary frame 21 there isarranged a rotating frame 22 such that the rotating frame is rotatableabout an axis B. When it is assumed that a direction into which theturn-over and hand-over mechanism 8 hands-over the pallet 9 is a forwarddirection, the stationary frame 21 and rotating frame 22 are formed tobe symmetrical in the right and left fashion as well as in the up anddown fashion except for parts of these frames. However, since therotating frame 22 is provided with an up and down moving mechanism to beexplained later, members and parts which are symmetrical in the rightand left fashion are denoted by the same reference numerals, but membersand parts which are symmetrical in the up and down fashion arerepresented by different reference numerals.

FIG. 3 is a plan view showing a part of the turn-over and hand-overmechanism 8 on an enlarged scale. A center of a front plate 21 a of thestationary frame 21 and a center of a front plate 22 a of the rotatingframe 22 are connected with each other in a rotatable manner by means ofa shaft 23, and similarly a center of a rear plate 21 b of thestationary frame 21 and a center of a rear plate 22 b of the rotatingframe 22 are connected with each other by means of a shaft not shown insuch a manner that the rear plate 22 b of the rotating frame 22 isrotated with respect to the rear plate 21 b of the stationary frame 21.A spacing between a side plate 21 c of the stationary frame 21 and aside plate 22 c of the rotating frame 22 is set to such a value thatthese side plates 21 c and 22 c are not brought into contact with eachother during the rotation of the rotating frame 22. As illustrated inFIG. 2, a driving motor 24 for rotating the rotating frame 22 isprovided at a depression 21 d formed at a center of the rear plate 21 bof the stationary frame 21, and the rotating frame 22 is rotated bymeans of the driving motor 24 in positive and negative directions by 180degrees.

FIG. 4 is a perspective view depicting the turn-over and hand-overmechanism 8 under such a condition that the rotating frame 22 is rotatedby 90 degrees in the right hand direction viewed in a direction from thefront plate 22 a to the rear plate 22 b, and the pallets 9 have beeninserted into the turn-over and hand-over mechanism 8. Also shown inFIG. 2, in each of inner surfaces of the side plates 22 c of therotating frame 22, there are formed first to fourth guide grooves 25-28for guiding the pallets 9. A spacing between the first and second guidegrooves 25 and 26 and a spacing between the third and fourth guidegrooves 27 and 28 are set such that when a pair of pallets are opposedto each other without forming a space therebetween, the disc D installedin the pallets is not dropped off the pallets during the rotation of therotating frame 22. The second guide groove 26 is separated from thethird guide groove 27 by a spacing which is larger than a width of thefront plate 21 a of the stationary frame 21 as well as a width of thefront plate 22 a of the rotating frame 22, such that the pallets 9situating in the horizontal plane may be easily inserted into the secondand third guide grooves 26 and 27.

It should be noted that the empty pallets 9 having no disc installedtherein have been previously inserted into the first and third guidegrooves 25 and 27. Furthermore, in order to insert easily the palletsinto the second and third guide grooves 26 and 27 in the horizontalposture, the front plates 21 a and 22 a have a small width.Alternatively, slots through which the pallets may be inserted may beformed in the front plates 21 a, 22 a.

FIG. 5 is a side view illustrating the rotating frame 22. In the sideplate 22 c of the rotating frame 22, there are formed first to fourthclaw guide slots 32 a-32 d for guiding claw members 30 and 31 in theforward and backward directions such that these slots are communicatedwith the first to fourth guide grooves 25-28, respectively, said clawmembers gripping the pallet 9. These claw guiding slots 32 a-32 d have awidth which is sufficiently small such that the pallet does not drop offthrough the slots. At a rear portion of the side plate 22 c, there areformed claw exchange slots 33 a and 33 b which serve to guide the clawmembers 30, 31 to move into suitable claw guide slots 32 a-32 d, saidrespective claw switching slots being communicated with the claw guideslots 32 a, 32 b and 32 c, 32 d, respectively.

In the side plate 22 c, there are formed slots 36 a, 36 b through whichforward and backward movable members 34, 35 are moved, and rails 37 a,37 b for supporting the forward and backward movable members 34, 35. Onan outer surface of a front portion of the side plate 22 c, a pushingmember 38 for pushing the claw members 30, 31 to rotate inwardly isprovided to be rotatable about a shaft 38 a which is secured to the sideplate 22 c . In the vicinity of the pushing plate 38 provide on theouter surface of the side plate 22 c, there is provided a solenoid 39having a rod 39 a for driving the pushing member 38.

In the manner explained above, on the rotating frame 22, there areprovided the first to fourth guide grooves 25-28, claw members 30, 31,first to fourth claw guide slots 32 a-32 d, slots 33 a, 33 b, slots 36a, 36 b, rails 37 a, 37 b, pushing member 38 and solenoid 39 in a rightand left symmetrical manner.

Again as shown in FIG. 2, the forward and backward movable members 34,35 are screwed to screw shafts 41 a, 41 b by means of connecting parts34 a, 35 a such that the forward and backward movable members moveforward and backward, said screw shafts being pivotally supported by therotating frame 22. On the outer surface of the rear plate 22 b of therotating frame 22, there are provided driving motors 42 a, 42 b forrotating the screw shafts 41 a, 41 b, respectively.

FIG. 6 is a partially enlarged view corresponding to FIG. 4 showing thecoupling mechanism between one of the claw members 31 and one of theforward and backward movable members 35, and the coupling mechanismbetween the other claw member 30 and the other forward and backwardmovable member 34 has a similar structure. The forward and backwardmovable members 34, 35 are movable in a direction C with respect to therotating frame 22, and the claw members 30, 31 are supported by theforward and backward movable members 34, 35 by means of the supportingshafts 43 a, 43 b, said claw members being slidable in a direction Dwith respect to the forward and backward movable members 34, 35 andbeing rotatable in a direction E. On outer surfaces of bearing portions44 a, 44 b provided integrally with the claw members 30, 31, there arearranged coiled springs 45 a, 45 b whose one ends are inserted intostopping holes 34 b, 34 d of the forward and backward movable members34, 35 such that the claw members 30, 31 are energized in the directionE. On the inner surfaces of the forward and backward movable members 34,35 there are provided rollers 46 a, 46 b which rotate on the rails 37 a,37 b.

In this manner, on the rotating frame 22 there are arranged the shafts43 a, 43 b, bearing portions 44 a, 44 b, coiled springs 45 a, 45 b androllers 46 a, 46 in the right and left symmetrical manner. It should benoted that the two forward and backward movable members 34, 35 areprovided one on the other, and the two screw shafts 41 a, 41 b arearranged in the right and left symmetrical manner.

In front of the rear plate 22 b of the rotating frame 22, there isarranged -shaped up and down movable member 47 which is coupled with therear plate 22 b by means of a guide member 48 and is movable in thedirection D. In the up and down movable member 47, there are formedslots 47 a, 47 b through which base portions 30 a, 31 a of the clawmembers 30, 31 are passed, and wider slots 36 a, 36 b through which theforward and backward movable members 34, 35 are passed. When the clawmembers 30, 31 are inserted into slots 47 a, 47 b formed in the up anddown movable member 47, thick portions 30 b, 31 b (thick portion 30 b isnot shown) are urged against the inner surface of the up and downmovable member 47 such that their outward movements are restricted.

The up and down movable member 47 constructed in the manner explainedabove moves downward by the gravitational force when the rotating frame22 is rotated, and one of the slots 47 a is aligned with the second clawguide slot 32 b and the other slot 47 b is aligned with the fourth clawguide slot 32 d. When the rotating frame 22 is rotated in the oppositedirection, the up and down movable member 47 moves also downward by thegravitational force, and one of the slots 47 a is aligned with the firstclaw guide slot 32 b and the other slot 47 b is aligned with the thirdclaw guide slot 32 d.

A pair of stoppers 49 a are provided on rear portions of the respectiveside plates 21 c of the stationary frame 21 and a pair of projections 49b are provided on upper and lower portions of one side of the up anddown movable member 47 such that the stoppers 49 a are brought intocontact with the projections in the rotating directions. Then, when therotating frame 22 is rotated in both directions, the up and down movablemember 47 may be forcedly moved downward.

As shown in FIG. 7 illustrating a partially cross sectional view of theturn-over and hand-over mechanism 8 constructed in the manner mentionedabove, at first, the empty pallets 9 are contained in the first guidegroove 25 and third guide groove 27, respectively in such a posture thatthe surfaces 11 are faced with the second guide groove 26 and fourthguide groove 28, respectively. The up and down movable member 47 movesdownward due to the gravitational force or the engagement of the stopper49 a with one of the projections 49 b, and the claw members 30 and 31are aligned with the second and fourth guide grooves 26 and 28,respectively.

Next, a control circuit of the transporting mechanism 4 sends a command,and the turn-over and hand-over mechanism 8 is moved by the transportingmechanism 4 in front of a desired storing box 2 as depicted in FIG. 8.Then, one of the driving motors 42 a of the turn-over and hand-overmechanism 8 rotates one of the screw shafts 41 a and one of the forwardand backward movable member 34 is moved forwardly. During this movement,the slide surface 30 c of the claw member 30 slides along the sidesurface of the up and down movable member 47 as well as along the bottomwall of the second guide groove 26 and projects forwardly beyond thefront plate 22 a of the rotating frame 22.

Then, the slide surface 30 c of the claw member 30 removes from thesecond guide groove 26, and the claw member 30 is rotated outwardly bythe force of the coiled spring 45 a. When the claw member 30 is movedforwardly into such a position that the engaging groove 30 d of the clawmember 30 can engage with the projection 13 of the pallet 9, thesolenoid 39 is driven and the slide surface 30 c of the claw member 30is pushed by the rod 39 a by means of the pushing member 38. Then, theprojection 13 of the pallet 9 is engaged with the engaging groove 30 dof the claw member 30 to grasp the pallet 9 by means of the claw member30.

After that, the screw shaft 41 a is rotated in the opposite direction bymeans of the driving motor 42 a to draw the claw member into the secondguide groove 26. At a time when the slide surface 30 c of the clawmember 30 can slide on the bottom wall of the second guide groove 26,the operation of the solenoid 39 is stopped and the pallet 9 having adesired disc D placed thereon is draw into the second guide groove 26while the claw member 30 is retained on the bottom wall of the secondguide groove 26. Then, the transporting mechanism 4 transports theturn-over and hand-over mechanism 8 in front of a desired storing box 2,and the other claw member 31 engages the pallet 9 having a desired discD placed thereon like as the claw member 30 and the pallet 9 is drawninto the fourth guide groove 28. In this manner, as illustrated in FIG.9, the four pallets 9 have been contained within the rotating frame 22.

After installing the desired discs D from the storing boxes 2 into theturn-over and hand-over mechanism 8, the transporting mechanism 4initiates to move the turn-over and hand-over mechanism 8 in front ofthe recording and reproducing drive 3. If it is required to turn-overthe discs D, the driving motor 24 is operated to rotate the rotatingframe 22 over 180 degrees. Since the empty pallets 9 have been containedwithin the first and third grooves 25 and 27, respectively, the discs Dare dropped onto these empty pallets 9 and are turned-over, as shown inFIG. 10 when the rotating frame 22 is rotated.

Upon the rotation of the rotating frame 22, the up and down movablemember 47 is moved downward due to the gravitational force or the actionof the stopper 49 a and the other projection 49 b, and the claw members30 and 31 are shifted downward to align with the lower third and firstguide members 27 and 25, respectively. As depicted in FIG. 11, aftermoving the turn-over and hand-over mechanism 8 in front of the recordingand reproducing drive 3 by means of the transporting mechanism 4 asshown in FIG. 11, the claw members 30, 31 are driven simultaneously orsuccessively to insert the pallets 9 supporting the turned-over discs Dinto the recording and reproducing drive 3.

During this operation, the solenoid 39 is driven and the claw members30, 31 are extruded into the input opening of the recording andreproducing derive 3, while the engaging grooves 30 d, 31 d of the clawmembers 30, 31 are engaged with the projections 13 of the pallets 9, andthe pallets 9 are inserted into the recording and reproducing drive 3.After that, the solenoid 39 is de-energized and the claw members 30, 31are rotated outwardly by the force of the coiled springs 45 a, 45 b torelieve the engagement between the engaging grooves 30 d, 31 d of theclaw members 30, 31 and the projections 13 of the pallets 9. Afterrelieving the pallets 9, the claw members 30, 31 are drawn into therotating frame 22.

In this manner, when the discs D are required to be turned-over, thediscs are turned-over within the turn-over and hand-over mechanism 8during the transportation to the recording and reproducing drive 3, butwhen it is not required to turn-over the discs D, the discs are insertedinto the recording and reproducing drive 3 without being turned-over. Byoperating the turn-over and hand-over mechanism 8 in the oppositemanner, the discs are taken out of the recording and reproducing driveand are returned into the storing boxes 2. In this case, the turned-overdiscs may be turned-over again by the turn-over and hand-over mechanism8 or may be returned into the storing box without being turned-over. Inthe case of returning the disc without being turned-over, the memory ofthe control circuit should store this fact.

In this manner, in the first embodiment, the empty pallets 9 have beenpreviously contained in the first and third guide grooves 25 and 27 insuch a posture that these pallets face downward, and then the pallets 9having the discs D placed thereon are inserted under the empty pallets 9such that the disc is sandwiched between the pallets 9. Therefore, whenthe rotating frame 22 is rotated by 180 degrees to turn-over the pallets9, the disc D do not drop off the pallets 9 and the turned-over discs Dcan be placed on the empty pallets 9.

Furthermore, by driving a pair of the claw members 30 and 31 uponexchanging a disc D installed in the recording and reproducing drive 3,a new disc D is transported into the recording and reproducing drive 3by means of the one claw member 30 and the existing disc D installed inthe recording and reproducing drive 3 can be drawn into the rotatingframe 22. Therefore, a time required for transporting the existing discD into the storing box 2 can be dispensed with, and the treating timecan be shortened. Moreover, even if one of the claw members 30, 31 mightbe out of order, the operation can be performed by means of the otherclaw member to attain a fail safe faculty. When a shortening of thetreating time and fail safe faculty are ignored, the turn-over andhand-over mechanism 8 may be constructed to include only a half of thehand-over mechanism.

FIG. 12 is a perspective view showing a second embodiment, in which apart of the housing 1 is shown by an imaginary line. On the post 7 issupported a hand-over mechanism 51 not having the turn-over facultyinstead of the turn-over and hand-over mechanism 8 of the firstembodiment, and within a housing 1 b provided under the recording andreproducing drive 3, is arranged a turn-over mechanism 52 shown in aperspective view of FIG. 13. In a pallet 9′, there are formed four holes16, and two pairs of iron chips 17 are provided in the vicinity of theprojections 13 of the pallet 9′. The hand-over mechanism 51 can merelyhand-over the pallet 9′ having the disc D placed thereon between thestoring box 2, the recording and reproducing drive 3 and the turn-overmechanism 52, and the turn-over mechanism 52 can turn-over the disc Dheld between the two pallets 9′.

In the turn-over mechanism 52, a rotating frame 54 is supportedrotatably by a bracket 53 secured to the housing 1 b, and the rotatingframe is rotated by means of a driving motor 55 secured to the bracket53. In inner surfaces of side plates 54 a of the rotating frame 54,there are formed two pairs of guide grooves 56 and 57 for guiding a pairof mutually opposing pallets 9′. Like as the first embodiment, a spacingbetween the guide grooves 56, 57 is set such that the disc D could notdrop off between the opposing pallets 9′. On an inner surface of a rearplate 54 b of the rotating frame 54, there are provided permanentmagnets 58 which can attract the iron chips 17 of the pallets 9′ withsuch a weak force that the pallets 9′ could be drawn without difficulty.

On an outer surface of one of the side plates 54 a of the rotating frame54, there are provided a projection 59 acting with a stopper and a flag60 for a sensor. To the bracket 53, there are provided a pair ofstoppers 61 for restring the movement of the projection 59 of therotating frame 54 and a pair of sensors 62 for detecting the flag 60. Onan upper bridging portion 54 c of the rotating frame 54, there isprovided light emitting unit 63 of an optical sensor for detecting aposition of the pallet 9′ by means of the holes 16 of the pallet, and ona lower bridging portion 54 d of the rotating frame 54 is provided alight receiving unit not shown which receives light from the lightemitting unit 63. The empty pallet 9′ has been previously inserted intothe upper guide grooves 56 of the turn-over mechanism 52.

When it is required to transport the disc D within the hand-overmechanism 51 to the recording and reproducing drive 3 without beingturned-over, the transporting mechanism 4 transports the hand-overmechanism 51 directly in front of the recording and reproducing drive 3,but when it is required to turn-over the disc D, the disc is oncetransported to the turn-over mechanism 52, and after turning-over thedisc D in the turn-over mechanism 52, the disc D is transported into therecording and reproducing drive 3.

When the transporting mechanism 4 transports the hand-over mechanism 51in front of the turn-over mechanism 52, the hand-over mechanism 51pushes the pallet 9′ having the disc D placed thereon into the lowerguide grooves 57 of the turn-over mechanism 52. Then, the magnet 58attracts the iron chip 17 of the pallet 9′, and the light receiving unitof the optical sensor receives light emitted by the light emitting unit63 through the holes 16 formed in the pallets 9′ to detect a conditionthat the upper and lower pallets 9′ are positioned at a correctposition. After that, the rotating frame 54 is rotated in a right handdirection viewed in the inserting direction of the pallet 9′ by means ofthe driving motor 55, and the rotation of the rotating frame 52 isstopped when the projection 59 is brought into contact with the otherstopper 61, which is detected by the other sensor 62. The turn-over ofthe disc D is completed and the disc D is placed on the lower pallet 9′.Then, the hand-over mechanism 51 draws the pallet 9′ having theturned-over disc D placed thereon from the turn-over mechanism 52, andthe transporting mechanism 4 transports the hand-over mechanism 51 infront of the recording and reproducing drive 3.

Upon returning the disc D for which the recording or reproducing hasbeen performed, into the original storing box 2, the turned-over disc Dmay be returned as it is and this fact is stored in the memory of thecontrol circuit, or before returning the disc D, the disc may betransported into the turn-over mechanism 52 and may be turned-over.

In this manner, in the second embodiment, the hand-over mechanism 51 andturn-over mechanism 52 for turning-over the disc D are providedseparately from each other instead of the turn-over and hand-overmechanism 8 of the first embodiment, and therefore the hand-overmechanism 51 and turn-over mechanism 52 can be simple in constructionand can be easily controlled. It should be noted that a plurality ofturn-over mechanisms 52 may be provided for shortening the transportingdistance of the hand-over mechanism 51.

It the first and second embodiments, the disc D is exchanged between thestoring box 2 and the recording and reproducing drive 3, but theinvention may be applied to the transportation of the disc into thestoring box and recording and reproducing drive 3. Furthermore, in theabove embodiments, the storing boxes 2 and recording and reproducingdrive 3 are provided on the same circle, but they may be arranged one onthe other. The transporting mechanism 4 transports the pallets 9, 9′between the storing boxes 2, the recording and reproducing drive 3 andthe turn-over mechanism 52 arranged on the same circle, but the pallets9, 9′ may be transported linearly between the storing boxes 2, therecording and reproducing drive 3 and the turn-over mechanism 52 whichare aligned linearly.

Moreover, a plurality of automatic disc exchange apparatuses may bearranged in series, and mechanisms for handing-over the pallets 9, 9′having discs D placed thereon between these automatic disc exchangeapparatuses. In this case, signals may be transmitted between theseautomatic disc exchange apparatuses as an infrared signal.

In the first and second embodiments, the pallets 9 are stacked such thata disc D could not drop off the pallets, but an intermediate platehaving an opening through which a disc D passes may be arranged betweenthe pallets 9. By providing such an intermediate plate, the disc D couldnot drop off the pallets, even if a spacing between the pallets is notso accurate. In this case, the intermediate plate has been previouslyarranged within the rotating frame 2 or the rotating frame 54.

Furthermore, the iron chip 17 and magnet 58 in the second embodiment maybe also provided on the pallet 9 and up and down movable member 47 ofthe first embodiment. Moreover, magnets for attracting the iron chips 17of the pallets 9, 9′ may be provided within the storing boxes 2. Then,the pallets 9, 9′ are retained in the storing boxes 2 with a weak forcewhich could not affect the drawing of the pallets 9, 9′. Then, thepallets 9, 9′ having the discs D placed thereon can be easily alignedwithin the storing box 2 and could not be easily moved due to vibration.

In the second embodiment, the optical sensor is used for detecting thatthe pallet 9′ is at a given position, but this may be detected bymechanical sensor or other sensor.

Applicability on the Industry

In the disc turn-over mechanism according to the invention, the firstpallet having a disc placed thereon and the second pallet having no discplaced thereon are stacked one on the other, and these first and secondpallets are turned-over by the turning-over means such that theturned-over disc is placed on the second pallet. Therefore, the dischaving the front and rear recording surfaces can be turned-over withoutbeing dropped off the pallets.

Since the automatic disc exchange apparatus according to the inventioncomprises the disc turn-over mechanism, the disc may be transportedbetween the storing means and the recording and reproducing means, whilethe disc is turned-over if necessary.

What is claimed is:
 1. A disc turn-over mechanism comprising at leasttwo pairs of first and second pallets, and a turning-over means forturning-over said first and second pallets, wherein said first pallet onwhich a disc is placed and said second pallet on which no disc is placedare stacked one on the other, and said disc is transferred onto thesecond pallet by turning-over the first and second pallets by saidturning-over means, the disc turn-over mechanism further comprising arotating frame rotatably supported by a stationary portion andcontaining said first and second pallets, a first driving mechanismsecured to said stationary portion and turning-over said rotating frameby 180 degrees from a substantially horizontal position to anothersubstantially horizontal position, claw members for grasping said firstand second pallets, and a second driving mechanism provided on saidrotating frame and driving said claw members forward and backward.
 2. Adisc turn-over mechanism as claimed in claim 1, wherein said rotatingframe includes guide grooves for guiding said first and second palletshorizontally in such a manner that the pallets are faced with eachother.
 3. A disc turn-over mechanism as claimed in claim 1, wherein saidmechanism further comprises a means for supporting said pallets in givenpositions within said rotating frame by means of a magnetic force.
 4. Adisc turn-over mechanism as claimed in claim 1, wherein said mechanismfurther comprises a means for detecting a condition that said palletsare in given positions.
 5. A disc turn-over mechanism as claimed inclaim 1, wherein said mechanism further comprises a means forrestricting the rotation of said rotating frame on a substantiallyhorizontal posture.
 6. A disc turn-over mechanism as claimed in claim 1,wherein said second pallet having no disc placed thereon has beenpreviously provided within the rotating frame, and said first pallethaving a disc placed thereon is stacked underneath the second pallet. 7.A disc-turn over mechanism as claimed in claim 1, further comprising amember for preventing said disc being dropped off through a space formedbetween said first and second pallets.
 8. A disc turn-over mechanismcomprising at least one pair of first and second pallets, and aturning-over means for turning-over said first and second pallets,wherein said first pallet on which a disc is placed and said secondpallet on which no disc is placed are stacked one on the other, and saiddisc is transferred onto the second pallet by turning-over the first andsecond pallets by said turning-over means, the disc turn-over mechanismfurther comprising a rotating frame rotatably supported by a stationaryportion and containing said first and second pallets, a first drivingmechanism secured to said stationary portion and turning-over saidrotating frame by 180 degrees from a substantially horizontal positionto another substantially horizontal position, claw members for graspingsaid first and second pallets, and a second driving mechanism providedon said rotating frame and driving said claw members forward andbackward, and said rotating frame including an up and down movablemember on which said claw members are provided, and when said rotatingframe is rotated, said up and down movable member is moved such thatsaid claw members are moved from positions corresponding to said firstpallet into positions corresponding to said second pallet.
 9. A discturn-over mechanism as claimed in claim 8, wherein said claw members aremoved into the positions corresponding to said second pallet by means ofthe gravitational force.
 10. A disc turn-over mechanism as claimed inclaim 8, wherein said mechanism further comprises a means for movingforcedly said claw members into the positions corresponding to saidsecond pallet.
 11. A disc turn-over mechanism as claimed in claim 8,wherein said rotating frame includes a third driving mechanism foropening and closing said claw members.
 12. A disc turn-over mechanism asclaimed in claim 8, wherein said up and down movable member includesplural pairs of claw members, said pallet is separating orsimultaneously pulled and drawn, and all said claw members aresimultaneously moved into the positions corresponding to said secondpallet.
 13. An automatic disc exchange apparatus comprising a storingmeans for storing discs placed on pallets, a recording and reproducingmeans for recording and reproducing information on and from said discs,a transporting means for transporting said discs between said storingmeans and said recording and reproducing apparatus, and a turn-overmechanism for turning-over discs, wherein said turn-over mechanismincludes at least two pairs of first and second pallets and aturning-over means for turning-over said first and second pallets whichcan place discs thereon, said first pallet on which a disc is placed andsaid second pallet on which no disc is placed are stacked one another,and said disc is transferred onto the second pallet by turning-over thefirst and second pallets by said turning-over means, said turn-overmechanism further comprising a rotating frame rotatably supported by astationary portion of said transporting means and containing said firstand second pallets, a first driving mechanism secured to said stationaryportion and turning-over said rotating frame by 180 degrees from asubstantially horizontal position to another substantially horizontalposition, claw members for grasping said first and second pallets, and asecond driving mechanism provided on said rotating frame driving saidclaw members forward and backward, whereby said disc can be turned-overduring the transportation by said transporting means.
 14. An automaticdisc exchange apparatus as claimed in claim 13, wherein said storingmeans and said recording and reproducing means are arranged on a samecircle such that their entrance and exit openings are faced inward withrespect to said circle, said transporting means is provided within saidcircle, and said turn-over mechanism is arranged such that its entranceand exit opening is faced outward with respect to said circle.
 15. Anautomatic disc exchange apparatus comprising a storing means for storingdiscs placed on pallets, a recording and reproducing means for recordingand reproducing information on and from said discs, a transporting meansfor transporting said discs between said storing means and saidrecording and reproducing apparatus, and a turn-over mechanism forturning-over discs, wherein said turn-over mechanism includes at leastone pair of first and second pallets and a turning-over means forturning-over said first and second pallets which can place discsthereon, said first pallet on which a disc is placed and said secondpallet on which no disc is placed are stacked one another, and said discis transferred onto the second pallet by turning-over the first andsecond pallets by said turning-over means, said turn-over mechanismfurther comprising a rotating frame rotatably supported by a stationaryportion of said transporting means and containing said first and secondpallets, a first driving mechanism secured to said stationary portionand turning-over said rotating frame by 180 degrees from a substantiallyhorizontal position to another substantially horizontal position, clawmembers for grasping said first and second pallets, and a second drivingmechanism provided on said rotating frame driving said claw membersforward and backward, whereby said disc can be turned-over during thetransportation by said transporting means, and said rotating frameincluding an up and down movable member on which said claw members areprovided, and when said rotating frame is rotated, said up and downmovable member is moved such that said claw members are moved frompositions corresponding to said first pallet into positionscorresponding to said second pallet.
 16. An automatic disc exchangeapparatus comprising a storing means for storing discs placed onpallets, a recording and reproducing means for recording and reproducinginformation on and from said discs, a transporting means fortransporting said discs between said storing means and said recordingand reproducing apparatus, and a turn-over mechanism for turning-overdiscs, wherein said turn-over mechanism includes at least one pair offirst and second. pallets and a turning-over means for turning-over saidfirst and second pallets which can place discs thereon, said firstpallet on which a disc is placed and said second pallet on which no discis placed are stacked one another, and said disc is transferred onto thesecond pallet by turning-over the first and second pallets by saidturning-over means, characterized in that said storing means, saidrecording and reproducing means and said turn-over mechanism arearranged on a same circle such that their entrance and exit openings arefaced inward with respect to said circle, and said transporting means isprovided within said circle such that its entrance and exit opening isfaced outward with respect to said circle.
 17. An automatic discexchange apparatus comprising a storing means for storing discs placedon pallets, a recording and reproducing means for recording andreproducing information on and from said discs, a transporting means fortransporting said discs between said storing means and said recordingand reproducing means, and a turn-over mechanism for turning-over discs,wherein said turn-over mechanism includes at least one pair of first andsecond pallets and a turning-over means for turning-over said first andsecond pallets which can place discs thereon, said first pallet on whicha disc is placed and said second pallet on which no disc is placed arestacked one on another, and said disc is transferred onto the secondpallet by turning-over the first and second pallets by said turning-overmeans, wherein said storing means, said recording and reproducing meansand said turn-over mechanism are arranged linearly, and the entrance andexit openings of said storing means, said recording and reproducingmeans and said turn-over mechanism are faced toward the entrance andexit opening of said transporting means.
 18. The automatic disc exchangeapparatus of claim 17 further comprising two pairs of first and secondpallets.